The present invention relates to pens or pencils and more particularly to combination pen casing which is axially combined with predetermined number of sleeves to define a cylindrical receiving space in the center to frictionally receive an ink cartridge of a ball pen or a lead of pencil.
Typical pencil casing as shown in FIG. 1 which includes a hollow cylinder casing 1, a number of lead sleeves 2 combinable disposed into the casing and a lead point 3 fixedly disposed in a front end of the sleeve 2. The lead point 3 has partially jutted out of the front end and engageable into a hollow interior in the rear end of the sleeves 2. When the lead point 3 of the first sleeve 2 is finished, insert a new one into the last sleeve 3 at the rear end of the casing 1. So that the first sleeve 2 is pushed away and replaced with a second sleeve 2. The way of replacement of the lead point 3 seems easy and convenient. But it wastes materials.
As for a paper wrapped crayon, when the point of the crayon is finished, one has to tear off a part the paper to jut another part of the crayon out. This process is not easy and causes the finger contaminated with the color of the crayon. Further, when the crayon leaves behind a small part, it is difficult to handle any more, but to cast away.